1. Field of the Invention
This invention relates to a signal recording apparatus and a signal reproducing apparatus. This invention also relates to a recording medium such as a magnetic tape.
2. Description of the Prior Art
One type of high-density magnetic recording of a video signal is segment recording in which every frame represented by the video signal is divided into a plurality of segments recorded on tracks on a magnetic tape via magnetic heads respectively. During a playback process, the recorded signal segments are reproduced from the tracks via the magnetic heads respectively. Generally, there are a plurality of signal processors related to the respective signal segments. During the playback process, a variation in characteristics among the signal processors causes a line flicker or a field flicker in indicated pictures generated from the reproduced signal segments.
An advanced high-vision VTR (video tape recorder) is designed to solve the above-indicated flicker problem (see ITEJ Technical Report, Vol. 15, No. 50, pp 1-6, Sep. 1991). The advanced high-vision VTR generates a plurality of corrective signals (calibration signals) designed to compensate for a variation in characteristics among signal processors. The corrective signals are recorded on starting potions of tracks on a magnetic tape. During a playback process, the corrective signals are reproduced from the tracks, and compensation for the variation in characteristics among the signal processors is executed in response to the reproduced corrective signals.
The advanced high-vision VTR has a problem such that recording of the corrective signals reduces the efficiency of use of the magnetic tape with respect to video information.
Some of magnetic recording and reproducing apparatus are of the deep-layer recording type in which an FM audio signal is recorded into a deep layer portion of a magnetic tape while a video signal, which results from frequency-multiplexing an FM luminance signal and frequency-down-converted color signals, is recorded on the magnetic tape.
Generally, an audio signal is of various types or modes such as a monophonic mode, a stereophonic mode, and a two-channel mode. An example of the two-channel mode is a bilingual mode in which main-channel information contains Japanese voices while sub-channel information contains English voices.
When such a two-channel audio signal is reproduced from a magnetic tape by the above-indicated apparatus of the deep-layer recording type, Japanese and English voices are simultaneously generated from loudspeakers in the apparatus. In such a case, the user is required to handle a manual switch in the apparatus to select desired one of the Japanese information and the English information.